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MPU9250.cpp@2:c7897a3f5f11, 2020-04-22 (annotated)

Committer:
demayer
Date:
Wed Apr 22 11:50:00 2020 +0000
Revision:
2:c7897a3f5f11
Parent:
1:b36bbc1c6d27 
test

Who changed what in which revision?

UserRevisionLine numberNew contents of line
demayer 1:b36bbc1c6d27 1 #include "MPU9250.h"
demayer 1:b36bbc1c6d27 2
demayer 1:b36bbc1c6d27 3
demayer 1:b36bbc1c6d27 4 uint8_t Ascale = AFS_2G; // AFS_2G, AFS_4G, AFS_8G, AFS_16G
demayer 1:b36bbc1c6d27 5 uint8_t Gscale = GFS_250DPS; // GFS_250DPS, GFS_500DPS, GFS_1000DPS, GFS_2000DPS
demayer 1:b36bbc1c6d27 6 uint8_t Mscale = MFS_16BITS; // MFS_14BITS or MFS_16BITS, 14-bit or 16-bit magnetometer resolution
demayer 1:b36bbc1c6d27 7 uint8_t Mmode = 0x06; // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR
demayer 1:b36bbc1c6d27 8 float aRes, gRes, mRes; // scale resolutions per LSB for the sensors
demayer 1:b36bbc1c6d27 9
demayer 1:b36bbc1c6d27 10 //Set up I2C, (SDA,SCL)
demayer 1:b36bbc1c6d27 11 I2C i2c(PB_9, PB_8);
demayer 1:b36bbc1c6d27 12
demayer 1:b36bbc1c6d27 13 DigitalOut myled(LED1);
demayer 1:b36bbc1c6d27 14
demayer 1:b36bbc1c6d27 15 // Pin definitions
demayer 1:b36bbc1c6d27 16 int intPin = 12; // These can be changed, 2 and 3 are the Arduinos ext int pins
demayer 1:b36bbc1c6d27 17
demayer 1:b36bbc1c6d27 18 int16_t accelCount[3]; // Stores the 16-bit signed accelerometer sensor output
demayer 1:b36bbc1c6d27 19 int16_t gyroCount[3]; // Stores the 16-bit signed gyro sensor output
demayer 1:b36bbc1c6d27 20 int16_t magCount[3]; // Stores the 16-bit signed magnetometer sensor output
demayer 1:b36bbc1c6d27 21 float magCalibration[3] = {0, 0, 0}, magbias[3] = {0, 0, 0}; // Factory mag calibration and mag bias
demayer 1:b36bbc1c6d27 22 float gyroBias[3] = {0, 0, 0}, accelBias[3] = {0, 0, 0}; // Bias corrections for gyro and accelerometer
demayer 1:b36bbc1c6d27 23 float ax, ay, az, gx, gy, gz, mx, my, mz; // variables to hold latest sensor data values
demayer 1:b36bbc1c6d27 24 int16_t tempCount; // Stores the real internal chip temperature in degrees Celsius
demayer 1:b36bbc1c6d27 25 float temperature;
demayer 1:b36bbc1c6d27 26 float SelfTest[6];
demayer 1:b36bbc1c6d27 27
demayer 1:b36bbc1c6d27 28 int delt_t = 0; // used to control display output rate
demayer 1:b36bbc1c6d27 29 int _count = 0; // used to control display output rate
demayer 1:b36bbc1c6d27 30
demayer 1:b36bbc1c6d27 31 // parameters for 6 DoF sensor fusion calculations
demayer 1:b36bbc1c6d27 32 float PI = 3.14159265358979323846f;
demayer 1:b36bbc1c6d27 33 float GyroMeasError = PI * (60.0f / 180.0f); // gyroscope measurement error in rads/s (start at 60 deg/s), then reduce after ~10 s to 3
demayer 1:b36bbc1c6d27 34 float beta = sqrt(3.0f / 4.0f) * GyroMeasError; // compute beta
demayer 1:b36bbc1c6d27 35 float GyroMeasDrift = PI * (1.0f / 180.0f); // gyroscope measurement drift in rad/s/s (start at 0.0 deg/s/s)
demayer 1:b36bbc1c6d27 36 float zeta = sqrt(3.0f / 4.0f) * GyroMeasDrift; // compute zeta, the other free parameter in the Madgwick scheme usually set to a small or zero value
demayer 1:b36bbc1c6d27 37 #define Kp 2.0f * 5.0f // these are the free parameters in the Mahony filter and fusion scheme, Kp for proportional feedback, Ki for integral
demayer 1:b36bbc1c6d27 38 #define Ki 0.0f
demayer 1:b36bbc1c6d27 39
demayer 1:b36bbc1c6d27 40 float pitch, yaw, roll;
demayer 1:b36bbc1c6d27 41 float vx, vy, vz;
demayer 1:b36bbc1c6d27 42 float deltat = 0.0f; // integration interval for both filter schemes
demayer 1:b36bbc1c6d27 43 int lastUpdate = 0, firstUpdate = 0, Now = 0; // used to calculate integration interval // used to calculate integration interval
demayer 1:b36bbc1c6d27 44 float q[4] = {1.0f, 0.0f, 0.0f, 0.0f}; // vector to hold quaternion
demayer 1:b36bbc1c6d27 45 float v_trans[3] = {0.0f, 0.0f, 0.0f}; // vector to hold translative velocities
demayer 1:b36bbc1c6d27 46 float a_old[3] = {0.00f, 0.00f, 0.00f};
demayer 1:b36bbc1c6d27 47 float eInt[3] = {0.0f, 0.0f, 0.0f}; // vector to hold integral error for Mahony method
demayer 1:b36bbc1c6d27 48
demayer 1:b36bbc1c6d27 49 accData_t myData;
demayer 1:b36bbc1c6d27 50 Timer t;
demayer 1:b36bbc1c6d27 51
demayer 1:b36bbc1c6d27 52 #define SAMPLE_TIME 100
demayer 1:b36bbc1c6d27 53
demayer 2:c7897a3f5f11 54 #define STEP_NUMBER 5
demayer 1:b36bbc1c6d27 55 float sum = 0;
demayer 1:b36bbc1c6d27 56 uint32_t sumCount = 0;
demayer 1:b36bbc1c6d27 57 char buffer[14];
demayer 2:c7897a3f5f11 58 float ax_sum = 0;
demayer 2:c7897a3f5f11 59 static float vx_buffer[STEP_NUMBER];
demayer 2:c7897a3f5f11 60 static int8_t stepCounter = 0;
demayer 2:c7897a3f5f11 61
demayer 2:c7897a3f5f11 62
demayer 2:c7897a3f5f11 63 // MPU9250-Constructor
demayer 2:c7897a3f5f11 64 MPU9250::MPU9250(Serial* serialPtr)
demayer 2:c7897a3f5f11 65 {
demayer 2:c7897a3f5f11 66 pc = serialPtr;
demayer 2:c7897a3f5f11 67 imuSetup();
demayer 2:c7897a3f5f11 68 vx_old = 0;
demayer 2:c7897a3f5f11 69 }
demayer 2:c7897a3f5f11 70
demayer 1:b36bbc1c6d27 71
demayer 1:b36bbc1c6d27 72
demayer 1:b36bbc1c6d27 73 //===================================================================================================================
demayer 1:b36bbc1c6d27 74 //====== Set of useful function to access acceleratio, gyroscope, and temperature data
demayer 1:b36bbc1c6d27 75 //===================================================================================================================
demayer 1:b36bbc1c6d27 76
demayer 1:b36bbc1c6d27 77 void MPU9250::writeByte(uint8_t address, uint8_t subAddress, uint8_t data)
demayer 1:b36bbc1c6d27 78 {
demayer 1:b36bbc1c6d27 79 char data_write[2];
demayer 1:b36bbc1c6d27 80 data_write[0] = subAddress;
demayer 1:b36bbc1c6d27 81 data_write[1] = data;
demayer 1:b36bbc1c6d27 82 i2c.write(address, data_write, 2, 0);
demayer 1:b36bbc1c6d27 83 }
demayer 1:b36bbc1c6d27 84
demayer 1:b36bbc1c6d27 85 char MPU9250::readByte(uint8_t address, uint8_t subAddress)
demayer 1:b36bbc1c6d27 86 {
demayer 1:b36bbc1c6d27 87 char data[1]; // `data` will store the register data
demayer 1:b36bbc1c6d27 88 char data_write[1];
demayer 1:b36bbc1c6d27 89 data_write[0] = subAddress;
demayer 1:b36bbc1c6d27 90 i2c.write(address, data_write, 1, 1); // no stop
demayer 1:b36bbc1c6d27 91 i2c.read(address, data, 1, 0);
demayer 1:b36bbc1c6d27 92 return data[0];
demayer 1:b36bbc1c6d27 93 }
demayer 1:b36bbc1c6d27 94
demayer 1:b36bbc1c6d27 95 void MPU9250::readBytes(uint8_t address, uint8_t subAddress, uint8_t count, uint8_t * dest)
demayer 1:b36bbc1c6d27 96 {
demayer 1:b36bbc1c6d27 97 char data[14];
demayer 1:b36bbc1c6d27 98 char data_write[1];
demayer 1:b36bbc1c6d27 99 data_write[0] = subAddress;
demayer 1:b36bbc1c6d27 100 i2c.write(address, data_write, 1, 1); // no stop
demayer 1:b36bbc1c6d27 101 i2c.read(address, data, count, 0);
demayer 1:b36bbc1c6d27 102 for(int ii = 0; ii < count; ii++) {
demayer 1:b36bbc1c6d27 103 dest[ii] = data[ii];
demayer 1:b36bbc1c6d27 104 }
demayer 1:b36bbc1c6d27 105 }
demayer 1:b36bbc1c6d27 106
demayer 1:b36bbc1c6d27 107
demayer 1:b36bbc1c6d27 108 void MPU9250::getMres()
demayer 1:b36bbc1c6d27 109 {
demayer 1:b36bbc1c6d27 110 switch (Mscale) {
demayer 1:b36bbc1c6d27 111 // Possible magnetometer scales (and their register bit settings) are:
demayer 1:b36bbc1c6d27 112 // 14 bit resolution (0) and 16 bit resolution (1)
demayer 1:b36bbc1c6d27 113 case MFS_14BITS:
demayer 1:b36bbc1c6d27 114 mRes = 10.0*4219.0/8190.0; // Proper scale to return milliGauss
demayer 1:b36bbc1c6d27 115 break;
demayer 1:b36bbc1c6d27 116 case MFS_16BITS:
demayer 1:b36bbc1c6d27 117 mRes = 10.0*4219.0/32760.0; // Proper scale to return milliGauss
demayer 1:b36bbc1c6d27 118 break;
demayer 1:b36bbc1c6d27 119 }
demayer 1:b36bbc1c6d27 120 }
demayer 1:b36bbc1c6d27 121
demayer 1:b36bbc1c6d27 122
demayer 1:b36bbc1c6d27 123 void MPU9250::getGres()
demayer 1:b36bbc1c6d27 124 {
demayer 1:b36bbc1c6d27 125 switch (Gscale) {
demayer 1:b36bbc1c6d27 126 // Possible gyro scales (and their register bit settings) are:
demayer 1:b36bbc1c6d27 127 // 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS (11).
demayer 1:b36bbc1c6d27 128 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
demayer 1:b36bbc1c6d27 129 case GFS_250DPS:
demayer 1:b36bbc1c6d27 130 gRes = 250.0/32768.0;
demayer 1:b36bbc1c6d27 131 break;
demayer 1:b36bbc1c6d27 132 case GFS_500DPS:
demayer 1:b36bbc1c6d27 133 gRes = 500.0/32768.0;
demayer 1:b36bbc1c6d27 134 break;
demayer 1:b36bbc1c6d27 135 case GFS_1000DPS:
demayer 1:b36bbc1c6d27 136 gRes = 1000.0/32768.0;
demayer 1:b36bbc1c6d27 137 break;
demayer 1:b36bbc1c6d27 138 case GFS_2000DPS:
demayer 1:b36bbc1c6d27 139 gRes = 2000.0/32768.0;
demayer 1:b36bbc1c6d27 140 break;
demayer 1:b36bbc1c6d27 141 }
demayer 1:b36bbc1c6d27 142 }
demayer 1:b36bbc1c6d27 143
demayer 1:b36bbc1c6d27 144
demayer 1:b36bbc1c6d27 145 void MPU9250::getAres()
demayer 1:b36bbc1c6d27 146 {
demayer 1:b36bbc1c6d27 147 switch (Ascale) {
demayer 1:b36bbc1c6d27 148 // Possible accelerometer scales (and their register bit settings) are:
demayer 1:b36bbc1c6d27 149 // 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs (11).
demayer 1:b36bbc1c6d27 150 // Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
demayer 1:b36bbc1c6d27 151 case AFS_2G:
demayer 1:b36bbc1c6d27 152 aRes = 2.0/32768.0;
demayer 1:b36bbc1c6d27 153 break;
demayer 1:b36bbc1c6d27 154 case AFS_4G:
demayer 1:b36bbc1c6d27 155 aRes = 4.0/32768.0;
demayer 1:b36bbc1c6d27 156 break;
demayer 1:b36bbc1c6d27 157 case AFS_8G:
demayer 1:b36bbc1c6d27 158 aRes = 8.0/32768.0;
demayer 1:b36bbc1c6d27 159 break;
demayer 1:b36bbc1c6d27 160 case AFS_16G:
demayer 1:b36bbc1c6d27 161 aRes = 16.0/32768.0;
demayer 1:b36bbc1c6d27 162 break;
demayer 1:b36bbc1c6d27 163 }
demayer 1:b36bbc1c6d27 164 }
demayer 1:b36bbc1c6d27 165
demayer 1:b36bbc1c6d27 166
demayer 1:b36bbc1c6d27 167 void MPU9250::readAccelData(int16_t * destination)
demayer 1:b36bbc1c6d27 168 {
demayer 1:b36bbc1c6d27 169 uint8_t rawData[6]; // x/y/z accel register data stored here
demayer 1:b36bbc1c6d27 170 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
demayer 1:b36bbc1c6d27 171 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 172 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 173 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 174 }
demayer 1:b36bbc1c6d27 175
demayer 1:b36bbc1c6d27 176 void MPU9250::readGyroData(int16_t * destination)
demayer 1:b36bbc1c6d27 177 {
demayer 1:b36bbc1c6d27 178 uint8_t rawData[6]; // x/y/z gyro register data stored here
demayer 1:b36bbc1c6d27 179 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
demayer 1:b36bbc1c6d27 180 destination[0] = (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 181 destination[1] = (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 182 destination[2] = (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 183 }
demayer 1:b36bbc1c6d27 184
demayer 1:b36bbc1c6d27 185 void MPU9250::readMagData(int16_t * destination)
demayer 1:b36bbc1c6d27 186 {
demayer 1:b36bbc1c6d27 187 uint8_t rawData[7]; // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition
demayer 1:b36bbc1c6d27 188 if(readByte(AK8963_ADDRESS, AK8963_ST1) & 0x01) { // wait for magnetometer data ready bit to be set
demayer 1:b36bbc1c6d27 189 readBytes(AK8963_ADDRESS, AK8963_XOUT_L, 7, &rawData[0]); // Read the six raw data and ST2 registers sequentially into data array
demayer 1:b36bbc1c6d27 190 uint8_t c = rawData[6]; // End data read by reading ST2 register
demayer 1:b36bbc1c6d27 191 if(!(c & 0x08)) { // Check if magnetic sensor overflow set, if not then report data
demayer 1:b36bbc1c6d27 192 destination[0] = (int16_t)(((int16_t)rawData[1] << 8) | rawData[0]); // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 193 destination[1] = (int16_t)(((int16_t)rawData[3] << 8) | rawData[2]) ; // Data stored as little Endian
demayer 1:b36bbc1c6d27 194 destination[2] = (int16_t)(((int16_t)rawData[5] << 8) | rawData[4]) ;
demayer 1:b36bbc1c6d27 195 }
demayer 1:b36bbc1c6d27 196 }
demayer 1:b36bbc1c6d27 197 }
demayer 1:b36bbc1c6d27 198
demayer 1:b36bbc1c6d27 199 int16_t MPU9250::readTempData()
demayer 1:b36bbc1c6d27 200 {
demayer 1:b36bbc1c6d27 201 uint8_t rawData[2]; // x/y/z gyro register data stored here
demayer 1:b36bbc1c6d27 202 readBytes(MPU9250_ADDRESS, TEMP_OUT_H, 2, &rawData[0]); // Read the two raw data registers sequentially into data array
demayer 1:b36bbc1c6d27 203 return (int16_t)(((int16_t)rawData[0]) << 8 | rawData[1]) ; // Turn the MSB and LSB into a 16-bit value
demayer 1:b36bbc1c6d27 204 }
demayer 1:b36bbc1c6d27 205
demayer 1:b36bbc1c6d27 206
demayer 1:b36bbc1c6d27 207 void MPU9250::resetMPU9250()
demayer 1:b36bbc1c6d27 208 {
demayer 1:b36bbc1c6d27 209 // reset device
demayer 1:b36bbc1c6d27 210 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
demayer 1:b36bbc1c6d27 211 wait(0.1);
demayer 1:b36bbc1c6d27 212 }
demayer 1:b36bbc1c6d27 213
demayer 1:b36bbc1c6d27 214 void MPU9250::initAK8963(float * destination)
demayer 1:b36bbc1c6d27 215 {
demayer 1:b36bbc1c6d27 216 // First extract the factory calibration for each magnetometer axis
demayer 1:b36bbc1c6d27 217 uint8_t rawData[3]; // x/y/z gyro calibration data stored here
demayer 1:b36bbc1c6d27 218 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
demayer 1:b36bbc1c6d27 219 wait(0.01);
demayer 1:b36bbc1c6d27 220 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x0F); // Enter Fuse ROM access mode
demayer 1:b36bbc1c6d27 221 wait(0.01);
demayer 1:b36bbc1c6d27 222 readBytes(AK8963_ADDRESS, AK8963_ASAX, 3, &rawData[0]); // Read the x-, y-, and z-axis calibration values
demayer 1:b36bbc1c6d27 223 destination[0] = (float)(rawData[0] - 128)/256.0f + 1.0f; // Return x-axis sensitivity adjustment values, etc.
demayer 1:b36bbc1c6d27 224 destination[1] = (float)(rawData[1] - 128)/256.0f + 1.0f;
demayer 1:b36bbc1c6d27 225 destination[2] = (float)(rawData[2] - 128)/256.0f + 1.0f;
demayer 1:b36bbc1c6d27 226 writeByte(AK8963_ADDRESS, AK8963_CNTL, 0x00); // Power down magnetometer
demayer 1:b36bbc1c6d27 227 wait(0.01);
demayer 1:b36bbc1c6d27 228 // Configure the magnetometer for continuous read and highest resolution
demayer 1:b36bbc1c6d27 229 // set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register,
demayer 1:b36bbc1c6d27 230 // and enable continuous mode data acquisition Mmode (bits [3:0]), 0010 for 8 Hz and 0110 for 100 Hz sample rates
demayer 1:b36bbc1c6d27 231 writeByte(AK8963_ADDRESS, AK8963_CNTL, Mscale << 4 | Mmode); // Set magnetometer data resolution and sample ODR
demayer 1:b36bbc1c6d27 232 wait(0.01);
demayer 1:b36bbc1c6d27 233 }
demayer 1:b36bbc1c6d27 234
demayer 1:b36bbc1c6d27 235
demayer 1:b36bbc1c6d27 236 void MPU9250::initMPU9250()
demayer 1:b36bbc1c6d27 237 {
demayer 1:b36bbc1c6d27 238 // Initialize MPU9250 device
demayer 1:b36bbc1c6d27 239 // wake up device
demayer 1:b36bbc1c6d27 240 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Clear sleep mode bit (6), enable all sensors
demayer 1:b36bbc1c6d27 241 wait(0.1); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt
demayer 1:b36bbc1c6d27 242
demayer 1:b36bbc1c6d27 243 // get stable time source
demayer 1:b36bbc1c6d27 244 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01); // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
demayer 1:b36bbc1c6d27 245
demayer 1:b36bbc1c6d27 246 // Configure Gyro and Accelerometer
demayer 1:b36bbc1c6d27 247 // Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively;
demayer 1:b36bbc1c6d27 248 // DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both
demayer 1:b36bbc1c6d27 249 // Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate
demayer 1:b36bbc1c6d27 250 writeByte(MPU9250_ADDRESS, CONFIG, 0x03);
demayer 1:b36bbc1c6d27 251
demayer 1:b36bbc1c6d27 252 // Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV)
demayer 1:b36bbc1c6d27 253 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x04); // Use a 200 Hz rate; the same rate set in CONFIG above
demayer 1:b36bbc1c6d27 254
demayer 1:b36bbc1c6d27 255 // Set gyroscope full scale range
demayer 1:b36bbc1c6d27 256 // Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3
demayer 1:b36bbc1c6d27 257 uint8_t c = readByte(MPU9250_ADDRESS, GYRO_CONFIG);
demayer 1:b36bbc1c6d27 258 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
demayer 1:b36bbc1c6d27 259 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
demayer 1:b36bbc1c6d27 260 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, c | Gscale << 3); // Set full scale range for the gyro
demayer 1:b36bbc1c6d27 261
demayer 1:b36bbc1c6d27 262 // Set accelerometer configuration
demayer 1:b36bbc1c6d27 263 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG);
demayer 1:b36bbc1c6d27 264 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0xE0); // Clear self-test bits [7:5]
demayer 1:b36bbc1c6d27 265 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c & ~0x18); // Clear AFS bits [4:3]
demayer 1:b36bbc1c6d27 266 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, c | Ascale << 3); // Set full scale range for the accelerometer
demayer 1:b36bbc1c6d27 267
demayer 1:b36bbc1c6d27 268 // Set accelerometer sample rate configuration
demayer 1:b36bbc1c6d27 269 // It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for
demayer 1:b36bbc1c6d27 270 // accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz
demayer 1:b36bbc1c6d27 271 c = readByte(MPU9250_ADDRESS, ACCEL_CONFIG2);
demayer 1:b36bbc1c6d27 272 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c & ~0x0F); // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0])
demayer 1:b36bbc1c6d27 273 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, c | 0x03); // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz
demayer 1:b36bbc1c6d27 274
demayer 1:b36bbc1c6d27 275 // The accelerometer, gyro, and thermometer are set to 1 kHz sample rates,
demayer 1:b36bbc1c6d27 276 // but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting
demayer 1:b36bbc1c6d27 277
demayer 1:b36bbc1c6d27 278 // Configure Interrupts and Bypass Enable
demayer 1:b36bbc1c6d27 279 // Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips
demayer 1:b36bbc1c6d27 280 // can join the I2C bus and all can be controlled by the Arduino as master
demayer 1:b36bbc1c6d27 281 writeByte(MPU9250_ADDRESS, INT_PIN_CFG, 0x22);
demayer 1:b36bbc1c6d27 282 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x01); // Enable data ready (bit 0) interrupt
demayer 1:b36bbc1c6d27 283 }
demayer 1:b36bbc1c6d27 284
demayer 1:b36bbc1c6d27 285 // Function which accumulates gyro and accelerometer data after device initialization. It calculates the average
demayer 1:b36bbc1c6d27 286 // of the at-rest readings and then loads the resulting offsets into accelerometer and gyro bias registers.
demayer 1:b36bbc1c6d27 287 void MPU9250::calibrateMPU9250(float * dest1, float * dest2)
demayer 1:b36bbc1c6d27 288 {
demayer 1:b36bbc1c6d27 289 uint8_t data[12]; // data array to hold accelerometer and gyro x, y, z, data
demayer 1:b36bbc1c6d27 290 uint16_t ii, packet_count, fifo_count;
demayer 1:b36bbc1c6d27 291 int32_t gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};
demayer 1:b36bbc1c6d27 292
demayer 1:b36bbc1c6d27 293 // reset device, reset all registers, clear gyro and accelerometer bias registers
demayer 1:b36bbc1c6d27 294 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
demayer 1:b36bbc1c6d27 295 wait(0.1);
demayer 1:b36bbc1c6d27 296
demayer 1:b36bbc1c6d27 297 // get stable time source
demayer 1:b36bbc1c6d27 298 // Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
demayer 1:b36bbc1c6d27 299 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x01);
demayer 1:b36bbc1c6d27 300 writeByte(MPU9250_ADDRESS, PWR_MGMT_2, 0x00);
demayer 1:b36bbc1c6d27 301 wait(0.2);
demayer 1:b36bbc1c6d27 302
demayer 1:b36bbc1c6d27 303 // Configure device for bias calculation
demayer 1:b36bbc1c6d27 304 writeByte(MPU9250_ADDRESS, INT_ENABLE, 0x00); // Disable all interrupts
demayer 1:b36bbc1c6d27 305 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable FIFO
demayer 1:b36bbc1c6d27 306 writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x00); // Turn on internal clock source
demayer 1:b36bbc1c6d27 307 writeByte(MPU9250_ADDRESS, I2C_MST_CTRL, 0x00); // Disable I2C master
demayer 1:b36bbc1c6d27 308 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x00); // Disable FIFO and I2C master modes
demayer 1:b36bbc1c6d27 309 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x0C); // Reset FIFO and DMP
demayer 1:b36bbc1c6d27 310 wait(0.015);
demayer 1:b36bbc1c6d27 311
demayer 1:b36bbc1c6d27 312 // Configure MPU9250 gyro and accelerometer for bias calculation
demayer 1:b36bbc1c6d27 313 writeByte(MPU9250_ADDRESS, CONFIG, 0x01); // Set low-pass filter to 188 Hz
demayer 1:b36bbc1c6d27 314 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz
demayer 1:b36bbc1c6d27 315 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity
demayer 1:b36bbc1c6d27 316 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity
demayer 1:b36bbc1c6d27 317
demayer 1:b36bbc1c6d27 318 uint16_t gyrosensitivity = 131; // = 131 LSB/degrees/sec
demayer 1:b36bbc1c6d27 319 uint16_t accelsensitivity = 16384; // = 16384 LSB/g
demayer 1:b36bbc1c6d27 320
demayer 1:b36bbc1c6d27 321 // Configure FIFO to capture accelerometer and gyro data for bias calculation
demayer 1:b36bbc1c6d27 322 writeByte(MPU9250_ADDRESS, USER_CTRL, 0x40); // Enable FIFO
demayer 1:b36bbc1c6d27 323 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x78); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250)
demayer 1:b36bbc1c6d27 324 wait(0.04); // accumulate 40 samples in 80 milliseconds = 480 bytes
demayer 1:b36bbc1c6d27 325
demayer 1:b36bbc1c6d27 326 // At end of sample accumulation, turn off FIFO sensor read
demayer 1:b36bbc1c6d27 327 writeByte(MPU9250_ADDRESS, FIFO_EN, 0x00); // Disable gyro and accelerometer sensors for FIFO
demayer 1:b36bbc1c6d27 328 readBytes(MPU9250_ADDRESS, FIFO_COUNTH, 2, &data[0]); // read FIFO sample count
demayer 1:b36bbc1c6d27 329 fifo_count = ((uint16_t)data[0] << 8) | data[1];
demayer 1:b36bbc1c6d27 330 packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging
demayer 1:b36bbc1c6d27 331
demayer 1:b36bbc1c6d27 332 for (ii = 0; ii < packet_count; ii++) {
demayer 1:b36bbc1c6d27 333 int16_t accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
demayer 1:b36bbc1c6d27 334 readBytes(MPU9250_ADDRESS, FIFO_R_W, 12, &data[0]); // read data for averaging
demayer 1:b36bbc1c6d27 335 accel_temp[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO
demayer 1:b36bbc1c6d27 336 accel_temp[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ;
demayer 1:b36bbc1c6d27 337 accel_temp[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ;
demayer 1:b36bbc1c6d27 338 gyro_temp[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ;
demayer 1:b36bbc1c6d27 339 gyro_temp[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ;
demayer 1:b36bbc1c6d27 340 gyro_temp[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
demayer 1:b36bbc1c6d27 341
demayer 1:b36bbc1c6d27 342 accel_bias[0] += (int32_t) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
demayer 1:b36bbc1c6d27 343 accel_bias[1] += (int32_t) accel_temp[1];
demayer 1:b36bbc1c6d27 344 accel_bias[2] += (int32_t) accel_temp[2];
demayer 1:b36bbc1c6d27 345 gyro_bias[0] += (int32_t) gyro_temp[0];
demayer 1:b36bbc1c6d27 346 gyro_bias[1] += (int32_t) gyro_temp[1];
demayer 1:b36bbc1c6d27 347 gyro_bias[2] += (int32_t) gyro_temp[2];
demayer 1:b36bbc1c6d27 348
demayer 1:b36bbc1c6d27 349 }
demayer 1:b36bbc1c6d27 350 accel_bias[0] /= (int32_t) packet_count; // Normalize sums to get average count biases
demayer 1:b36bbc1c6d27 351 accel_bias[1] /= (int32_t) packet_count;
demayer 1:b36bbc1c6d27 352 accel_bias[2] /= (int32_t) packet_count;
demayer 1:b36bbc1c6d27 353 gyro_bias[0] /= (int32_t) packet_count;
demayer 1:b36bbc1c6d27 354 gyro_bias[1] /= (int32_t) packet_count;
demayer 1:b36bbc1c6d27 355 gyro_bias[2] /= (int32_t) packet_count;
demayer 1:b36bbc1c6d27 356
demayer 1:b36bbc1c6d27 357 if(accel_bias[2] > 0L) {
demayer 1:b36bbc1c6d27 358 accel_bias[2] -= (int32_t) accelsensitivity; // Remove gravity from the z-axis accelerometer bias calculation
demayer 1:b36bbc1c6d27 359 } else {
demayer 1:b36bbc1c6d27 360 accel_bias[2] += (int32_t) accelsensitivity;
demayer 1:b36bbc1c6d27 361 }
demayer 1:b36bbc1c6d27 362
demayer 1:b36bbc1c6d27 363 // Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup
demayer 1:b36bbc1c6d27 364 data[0] = (-gyro_bias[0]/4 >> 8) & 0xFF; // Divide by 4 to get 32.9 LSB per deg/s to conform to expected bias input format
demayer 1:b36bbc1c6d27 365 data[1] = (-gyro_bias[0]/4) & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
demayer 1:b36bbc1c6d27 366 data[2] = (-gyro_bias[1]/4 >> 8) & 0xFF;
demayer 1:b36bbc1c6d27 367 data[3] = (-gyro_bias[1]/4) & 0xFF;
demayer 1:b36bbc1c6d27 368 data[4] = (-gyro_bias[2]/4 >> 8) & 0xFF;
demayer 1:b36bbc1c6d27 369 data[5] = (-gyro_bias[2]/4) & 0xFF;
demayer 1:b36bbc1c6d27 370
demayer 1:b36bbc1c6d27 371 /// Push gyro biases to hardware registers
demayer 1:b36bbc1c6d27 372 /* writeByte(MPU9250_ADDRESS, XG_OFFSET_H, data[0]);
demayer 1:b36bbc1c6d27 373 writeByte(MPU9250_ADDRESS, XG_OFFSET_L, data[1]);
demayer 1:b36bbc1c6d27 374 writeByte(MPU9250_ADDRESS, YG_OFFSET_H, data[2]);
demayer 1:b36bbc1c6d27 375 writeByte(MPU9250_ADDRESS, YG_OFFSET_L, data[3]);
demayer 1:b36bbc1c6d27 376 writeByte(MPU9250_ADDRESS, ZG_OFFSET_H, data[4]);
demayer 1:b36bbc1c6d27 377 writeByte(MPU9250_ADDRESS, ZG_OFFSET_L, data[5]);
demayer 1:b36bbc1c6d27 378 */
demayer 1:b36bbc1c6d27 379 dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction
demayer 1:b36bbc1c6d27 380 dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity;
demayer 1:b36bbc1c6d27 381 dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity;
demayer 1:b36bbc1c6d27 382
demayer 1:b36bbc1c6d27 383 // Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain
demayer 1:b36bbc1c6d27 384 // factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold
demayer 1:b36bbc1c6d27 385 // non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature
demayer 1:b36bbc1c6d27 386 // compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that
demayer 1:b36bbc1c6d27 387 // the accelerometer biases calculated above must be divided by 8.
demayer 1:b36bbc1c6d27 388
demayer 1:b36bbc1c6d27 389 int32_t accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
demayer 1:b36bbc1c6d27 390 readBytes(MPU9250_ADDRESS, XA_OFFSET_H, 2, &data[0]); // Read factory accelerometer trim values
demayer 1:b36bbc1c6d27 391 accel_bias_reg[0] = (int16_t) ((int16_t)data[0] << 8) | data[1];
demayer 1:b36bbc1c6d27 392 readBytes(MPU9250_ADDRESS, YA_OFFSET_H, 2, &data[0]);
demayer 1:b36bbc1c6d27 393 accel_bias_reg[1] = (int16_t) ((int16_t)data[0] << 8) | data[1];
demayer 1:b36bbc1c6d27 394 readBytes(MPU9250_ADDRESS, ZA_OFFSET_H, 2, &data[0]);
demayer 1:b36bbc1c6d27 395 accel_bias_reg[2] = (int16_t) ((int16_t)data[0] << 8) | data[1];
demayer 1:b36bbc1c6d27 396
demayer 1:b36bbc1c6d27 397 uint32_t mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers
demayer 1:b36bbc1c6d27 398 uint8_t mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis
demayer 1:b36bbc1c6d27 399
demayer 1:b36bbc1c6d27 400 for(ii = 0; ii < 3; ii++) {
demayer 1:b36bbc1c6d27 401 if(accel_bias_reg[ii] & mask) mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit
demayer 1:b36bbc1c6d27 402 }
demayer 1:b36bbc1c6d27 403
demayer 1:b36bbc1c6d27 404 // Construct total accelerometer bias, including calculated average accelerometer bias from above
demayer 1:b36bbc1c6d27 405 accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
demayer 1:b36bbc1c6d27 406 accel_bias_reg[1] -= (accel_bias[1]/8);
demayer 1:b36bbc1c6d27 407 accel_bias_reg[2] -= (accel_bias[2]/8);
demayer 1:b36bbc1c6d27 408
demayer 1:b36bbc1c6d27 409 data[0] = (accel_bias_reg[0] >> 8) & 0xFF;
demayer 1:b36bbc1c6d27 410 data[1] = (accel_bias_reg[0]) & 0xFF;
demayer 1:b36bbc1c6d27 411 data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers
demayer 1:b36bbc1c6d27 412 data[2] = (accel_bias_reg[1] >> 8) & 0xFF;
demayer 1:b36bbc1c6d27 413 data[3] = (accel_bias_reg[1]) & 0xFF;
demayer 1:b36bbc1c6d27 414 data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers
demayer 1:b36bbc1c6d27 415 data[4] = (accel_bias_reg[2] >> 8) & 0xFF;
demayer 1:b36bbc1c6d27 416 data[5] = (accel_bias_reg[2]) & 0xFF;
demayer 1:b36bbc1c6d27 417 data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers
demayer 1:b36bbc1c6d27 418
demayer 1:b36bbc1c6d27 419 // Apparently this is not working for the acceleration biases in the MPU-9250
demayer 1:b36bbc1c6d27 420 // Are we handling the temperature correction bit properly?
demayer 1:b36bbc1c6d27 421 // Push accelerometer biases to hardware registers
demayer 1:b36bbc1c6d27 422 /* writeByte(MPU9250_ADDRESS, XA_OFFSET_H, data[0]);
demayer 1:b36bbc1c6d27 423 writeByte(MPU9250_ADDRESS, XA_OFFSET_L, data[1]);
demayer 1:b36bbc1c6d27 424 writeByte(MPU9250_ADDRESS, YA_OFFSET_H, data[2]);
demayer 1:b36bbc1c6d27 425 writeByte(MPU9250_ADDRESS, YA_OFFSET_L, data[3]);
demayer 1:b36bbc1c6d27 426 writeByte(MPU9250_ADDRESS, ZA_OFFSET_H, data[4]);
demayer 1:b36bbc1c6d27 427 writeByte(MPU9250_ADDRESS, ZA_OFFSET_L, data[5]);
demayer 1:b36bbc1c6d27 428 */
demayer 1:b36bbc1c6d27 429 // Output scaled accelerometer biases for manual subtraction in the main program
demayer 1:b36bbc1c6d27 430 dest2[0] = (float)accel_bias[0]/(float)accelsensitivity;
demayer 1:b36bbc1c6d27 431 dest2[1] = (float)accel_bias[1]/(float)accelsensitivity;
demayer 1:b36bbc1c6d27 432 dest2[2] = (float)accel_bias[2]/(float)accelsensitivity;
demayer 1:b36bbc1c6d27 433 }
demayer 1:b36bbc1c6d27 434
demayer 1:b36bbc1c6d27 435
demayer 1:b36bbc1c6d27 436 // Accelerometer and gyroscope self test; check calibration wrt factory settings
demayer 1:b36bbc1c6d27 437 void MPU9250::MPU9250SelfTest(float * destination) // Should return percent deviation from factory trim values, +/- 14 or less deviation is a pass
demayer 1:b36bbc1c6d27 438 {
demayer 1:b36bbc1c6d27 439 uint8_t rawData[6] = {0, 0, 0, 0, 0, 0};
demayer 1:b36bbc1c6d27 440 uint8_t selfTest[6];
demayer 1:b36bbc1c6d27 441 int16_t gAvg[3], aAvg[3], aSTAvg[3], gSTAvg[3];
demayer 1:b36bbc1c6d27 442 float factoryTrim[6];
demayer 1:b36bbc1c6d27 443 uint8_t FS = 0;
demayer 1:b36bbc1c6d27 444
demayer 1:b36bbc1c6d27 445 writeByte(MPU9250_ADDRESS, SMPLRT_DIV, 0x00); // Set gyro sample rate to 1 kHz
demayer 1:b36bbc1c6d27 446 writeByte(MPU9250_ADDRESS, CONFIG, 0x02); // Set gyro sample rate to 1 kHz and DLPF to 92 Hz
demayer 1:b36bbc1c6d27 447 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 1<<FS); // Set full scale range for the gyro to 250 dps
demayer 1:b36bbc1c6d27 448 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG2, 0x02); // Set accelerometer rate to 1 kHz and bandwidth to 92 Hz
demayer 1:b36bbc1c6d27 449 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 1<<FS); // Set full scale range for the accelerometer to 2 g
demayer 1:b36bbc1c6d27 450
demayer 1:b36bbc1c6d27 451 for( int ii = 0; ii < 200; ii++) { // get average current values of gyro and acclerometer
demayer 1:b36bbc1c6d27 452
demayer 1:b36bbc1c6d27 453 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
demayer 1:b36bbc1c6d27 454 aAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 455 aAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 456 aAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 457
demayer 1:b36bbc1c6d27 458 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
demayer 1:b36bbc1c6d27 459 gAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 460 gAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 461 gAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 462 }
demayer 1:b36bbc1c6d27 463
demayer 1:b36bbc1c6d27 464 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average current readings
demayer 1:b36bbc1c6d27 465 aAvg[ii] /= 200;
demayer 1:b36bbc1c6d27 466 gAvg[ii] /= 200;
demayer 1:b36bbc1c6d27 467 }
demayer 1:b36bbc1c6d27 468
demayer 1:b36bbc1c6d27 469 // Configure the accelerometer for self-test
demayer 1:b36bbc1c6d27 470 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0xE0); // Enable self test on all three axes and set accelerometer range to +/- 2 g
demayer 1:b36bbc1c6d27 471 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0xE0); // Enable self test on all three axes and set gyro range to +/- 250 degrees/s
demayer 1:b36bbc1c6d27 472 wait(0.025); // Delay a while to let the device stabilize
demayer 1:b36bbc1c6d27 473
demayer 1:b36bbc1c6d27 474 for( int ii = 0; ii < 200; ii++) { // get average self-test values of gyro and acclerometer
demayer 1:b36bbc1c6d27 475
demayer 1:b36bbc1c6d27 476 readBytes(MPU9250_ADDRESS, ACCEL_XOUT_H, 6, &rawData[0]); // Read the six raw data registers into data array
demayer 1:b36bbc1c6d27 477 aSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 478 aSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 479 aSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 480
demayer 1:b36bbc1c6d27 481 readBytes(MPU9250_ADDRESS, GYRO_XOUT_H, 6, &rawData[0]); // Read the six raw data registers sequentially into data array
demayer 1:b36bbc1c6d27 482 gSTAvg[0] += (int16_t)(((int16_t)rawData[0] << 8) | rawData[1]) ; // Turn the MSB and LSB into a signed 16-bit value
demayer 1:b36bbc1c6d27 483 gSTAvg[1] += (int16_t)(((int16_t)rawData[2] << 8) | rawData[3]) ;
demayer 1:b36bbc1c6d27 484 gSTAvg[2] += (int16_t)(((int16_t)rawData[4] << 8) | rawData[5]) ;
demayer 1:b36bbc1c6d27 485 }
demayer 1:b36bbc1c6d27 486
demayer 1:b36bbc1c6d27 487 for (int ii =0; ii < 3; ii++) { // Get average of 200 values and store as average self-test readings
demayer 1:b36bbc1c6d27 488 aSTAvg[ii] /= 200;
demayer 1:b36bbc1c6d27 489 gSTAvg[ii] /= 200;
demayer 1:b36bbc1c6d27 490 }
demayer 1:b36bbc1c6d27 491
demayer 1:b36bbc1c6d27 492 // Configure the gyro and accelerometer for normal operation
demayer 1:b36bbc1c6d27 493 writeByte(MPU9250_ADDRESS, ACCEL_CONFIG, 0x00);
demayer 1:b36bbc1c6d27 494 writeByte(MPU9250_ADDRESS, GYRO_CONFIG, 0x00);
demayer 1:b36bbc1c6d27 495 wait(0.025); // Delay a while to let the device stabilize
demayer 1:b36bbc1c6d27 496
demayer 1:b36bbc1c6d27 497 // Retrieve accelerometer and gyro factory Self-Test Code from USR_Reg
demayer 1:b36bbc1c6d27 498 selfTest[0] = readByte(MPU9250_ADDRESS, SELF_TEST_X_ACCEL); // X-axis accel self-test results
demayer 1:b36bbc1c6d27 499 selfTest[1] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_ACCEL); // Y-axis accel self-test results
demayer 1:b36bbc1c6d27 500 selfTest[2] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_ACCEL); // Z-axis accel self-test results
demayer 1:b36bbc1c6d27 501 selfTest[3] = readByte(MPU9250_ADDRESS, SELF_TEST_X_GYRO); // X-axis gyro self-test results
demayer 1:b36bbc1c6d27 502 selfTest[4] = readByte(MPU9250_ADDRESS, SELF_TEST_Y_GYRO); // Y-axis gyro self-test results
demayer 1:b36bbc1c6d27 503 selfTest[5] = readByte(MPU9250_ADDRESS, SELF_TEST_Z_GYRO); // Z-axis gyro self-test results
demayer 1:b36bbc1c6d27 504
demayer 1:b36bbc1c6d27 505 // Retrieve factory self-test value from self-test code reads
demayer 1:b36bbc1c6d27 506 factoryTrim[0] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[0] - 1.0) )); // FT[Xa] factory trim calculation
demayer 1:b36bbc1c6d27 507 factoryTrim[1] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[1] - 1.0) )); // FT[Ya] factory trim calculation
demayer 1:b36bbc1c6d27 508 factoryTrim[2] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[2] - 1.0) )); // FT[Za] factory trim calculation
demayer 1:b36bbc1c6d27 509 factoryTrim[3] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[3] - 1.0) )); // FT[Xg] factory trim calculation
demayer 1:b36bbc1c6d27 510 factoryTrim[4] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[4] - 1.0) )); // FT[Yg] factory trim calculation
demayer 1:b36bbc1c6d27 511 factoryTrim[5] = (float)(2620/1<<FS)*(pow( 1.01, ((float)selfTest[5] - 1.0) )); // FT[Zg] factory trim calculation
demayer 1:b36bbc1c6d27 512
demayer 1:b36bbc1c6d27 513 // Report results as a ratio of (STR - FT)/FT; the change from Factory Trim of the Self-Test Response
demayer 1:b36bbc1c6d27 514 // To get percent, must multiply by 100
demayer 1:b36bbc1c6d27 515 for (int i = 0; i < 3; i++) {
demayer 1:b36bbc1c6d27 516 destination[i] = 100.0*((float)(aSTAvg[i] - aAvg[i]))/factoryTrim[i]; // Report percent differences
demayer 1:b36bbc1c6d27 517 destination[i+3] = 100.0*((float)(gSTAvg[i] - gAvg[i]))/factoryTrim[i+3]; // Report percent differences
demayer 1:b36bbc1c6d27 518 }
demayer 1:b36bbc1c6d27 519
demayer 1:b36bbc1c6d27 520 }
demayer 1:b36bbc1c6d27 521
demayer 1:b36bbc1c6d27 522
demayer 1:b36bbc1c6d27 523
demayer 1:b36bbc1c6d27 524 // Implementation of Sebastian Madgwick's "...efficient orientation filter for... inertial/magnetic sensor arrays"
demayer 1:b36bbc1c6d27 525 // (see http://www.x-io.co.uk/category/open-source/ for examples and more details)
demayer 1:b36bbc1c6d27 526 // which fuses acceleration, rotation rate, and magnetic moments to produce a quaternion-based estimate of absolute
demayer 1:b36bbc1c6d27 527 // device orientation -- which can be converted to yaw, pitch, and roll. Useful for stabilizing quadcopters, etc.
demayer 1:b36bbc1c6d27 528 // The performance of the orientation filter is at least as good as conventional Kalman-based filtering algorithms
demayer 1:b36bbc1c6d27 529 // but is much less computationally intensive---it can be performed on a 3.3 V Pro Mini operating at 8 MHz!
demayer 1:b36bbc1c6d27 530 void MPU9250::MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz)
demayer 1:b36bbc1c6d27 531 {
demayer 1:b36bbc1c6d27 532 float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3]; // short name local variable for readability
demayer 1:b36bbc1c6d27 533 float norm;
demayer 1:b36bbc1c6d27 534 float hx, hy, _2bx, _2bz;
demayer 1:b36bbc1c6d27 535 float s1, s2, s3, s4;
demayer 1:b36bbc1c6d27 536 float qDot1, qDot2, qDot3, qDot4;
demayer 1:b36bbc1c6d27 537
demayer 1:b36bbc1c6d27 538 // Auxiliary variables to avoid repeated arithmetic
demayer 1:b36bbc1c6d27 539 float _2q1mx;
demayer 1:b36bbc1c6d27 540 float _2q1my;
demayer 1:b36bbc1c6d27 541 float _2q1mz;
demayer 1:b36bbc1c6d27 542 float _2q2mx;
demayer 1:b36bbc1c6d27 543 float _4bx;
demayer 1:b36bbc1c6d27 544 float _4bz;
demayer 1:b36bbc1c6d27 545 float _2q1 = 2.0f * q1;
demayer 1:b36bbc1c6d27 546 float _2q2 = 2.0f * q2;
demayer 1:b36bbc1c6d27 547 float _2q3 = 2.0f * q3;
demayer 1:b36bbc1c6d27 548 float _2q4 = 2.0f * q4;
demayer 1:b36bbc1c6d27 549 float _2q1q3 = 2.0f * q1 * q3;
demayer 1:b36bbc1c6d27 550 float _2q3q4 = 2.0f * q3 * q4;
demayer 1:b36bbc1c6d27 551 float q1q1 = q1 * q1;
demayer 1:b36bbc1c6d27 552 float q1q2 = q1 * q2;
demayer 1:b36bbc1c6d27 553 float q1q3 = q1 * q3;
demayer 1:b36bbc1c6d27 554 float q1q4 = q1 * q4;
demayer 1:b36bbc1c6d27 555 float q2q2 = q2 * q2;
demayer 1:b36bbc1c6d27 556 float q2q3 = q2 * q3;
demayer 1:b36bbc1c6d27 557 float q2q4 = q2 * q4;
demayer 1:b36bbc1c6d27 558 float q3q3 = q3 * q3;
demayer 1:b36bbc1c6d27 559 float q3q4 = q3 * q4;
demayer 1:b36bbc1c6d27 560 float q4q4 = q4 * q4;
demayer 1:b36bbc1c6d27 561
demayer 1:b36bbc1c6d27 562 // Normalise accelerometer measurement
demayer 1:b36bbc1c6d27 563 norm = sqrt(ax * ax + ay * ay + az * az);
demayer 1:b36bbc1c6d27 564 if (norm == 0.0f) return; // handle NaN
demayer 1:b36bbc1c6d27 565 norm = 1.0f/norm;
demayer 1:b36bbc1c6d27 566 ax *= norm;
demayer 1:b36bbc1c6d27 567 ay *= norm;
demayer 1:b36bbc1c6d27 568 az *= norm;
demayer 1:b36bbc1c6d27 569
demayer 1:b36bbc1c6d27 570 // Normalise magnetometer measurement
demayer 1:b36bbc1c6d27 571 norm = sqrt(mx * mx + my * my + mz * mz);
demayer 1:b36bbc1c6d27 572 if (norm == 0.0f) return; // handle NaN
demayer 1:b36bbc1c6d27 573 norm = 1.0f/norm;
demayer 1:b36bbc1c6d27 574 mx *= norm;
demayer 1:b36bbc1c6d27 575 my *= norm;
demayer 1:b36bbc1c6d27 576 mz *= norm;
demayer 1:b36bbc1c6d27 577
demayer 1:b36bbc1c6d27 578 // Reference direction of Earth's magnetic field
demayer 1:b36bbc1c6d27 579 _2q1mx = 2.0f * q1 * mx;
demayer 1:b36bbc1c6d27 580 _2q1my = 2.0f * q1 * my;
demayer 1:b36bbc1c6d27 581 _2q1mz = 2.0f * q1 * mz;
demayer 1:b36bbc1c6d27 582 _2q2mx = 2.0f * q2 * mx;
demayer 1:b36bbc1c6d27 583 hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4;
demayer 1:b36bbc1c6d27 584 hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4;
demayer 1:b36bbc1c6d27 585 _2bx = sqrt(hx * hx + hy * hy);
demayer 1:b36bbc1c6d27 586 _2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4;
demayer 1:b36bbc1c6d27 587 _4bx = 2.0f * _2bx;
demayer 1:b36bbc1c6d27 588 _4bz = 2.0f * _2bz;
demayer 1:b36bbc1c6d27 589
demayer 1:b36bbc1c6d27 590 // Gradient decent algorithm corrective step
demayer 1:b36bbc1c6d27 591 s1 = -_2q3 * (2.0f * q2q4 - _2q1q3 - ax) + _2q2 * (2.0f * q1q2 + _2q3q4 - ay) - _2bz * q3 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q4 + _2bz * q2) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q3 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
demayer 1:b36bbc1c6d27 592 s2 = _2q4 * (2.0f * q2q4 - _2q1q3 - ax) + _2q1 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q2 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + _2bz * q4 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q3 + _2bz * q1) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q4 - _4bz * q2) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
demayer 1:b36bbc1c6d27 593 s3 = -_2q1 * (2.0f * q2q4 - _2q1q3 - ax) + _2q4 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q3 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + (-_4bx * q3 - _2bz * q1) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q2 + _2bz * q4) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q1 - _4bz * q3) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
demayer 1:b36bbc1c6d27 594 s4 = _2q2 * (2.0f * q2q4 - _2q1q3 - ax) + _2q3 * (2.0f * q1q2 + _2q3q4 - ay) + (-_4bx * q4 + _2bz * q2) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q1 + _2bz * q3) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q2 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
demayer 1:b36bbc1c6d27 595 norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4); // normalise step magnitude
demayer 1:b36bbc1c6d27 596 norm = 1.0f/norm;
demayer 1:b36bbc1c6d27 597 s1 *= norm;
demayer 1:b36bbc1c6d27 598 s2 *= norm;
demayer 1:b36bbc1c6d27 599 s3 *= norm;
demayer 1:b36bbc1c6d27 600 s4 *= norm;
demayer 1:b36bbc1c6d27 601
demayer 1:b36bbc1c6d27 602 // Compute rate of change of quaternion
demayer 1:b36bbc1c6d27 603 qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1;
demayer 1:b36bbc1c6d27 604 qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2;
demayer 1:b36bbc1c6d27 605 qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3;
demayer 1:b36bbc1c6d27 606 qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4;
demayer 1:b36bbc1c6d27 607
demayer 1:b36bbc1c6d27 608 // Integrate to yield quaternion
demayer 1:b36bbc1c6d27 609 q1 += qDot1 * deltat;
demayer 1:b36bbc1c6d27 610 q2 += qDot2 * deltat;
demayer 1:b36bbc1c6d27 611 q3 += qDot3 * deltat;
demayer 1:b36bbc1c6d27 612 q4 += qDot4 * deltat;
demayer 1:b36bbc1c6d27 613 norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4); // normalise quaternion
demayer 1:b36bbc1c6d27 614 norm = 1.0f/norm;
demayer 1:b36bbc1c6d27 615 q[0] = q1 * norm;
demayer 1:b36bbc1c6d27 616 q[1] = q2 * norm;
demayer 1:b36bbc1c6d27 617 q[2] = q3 * norm;
demayer 1:b36bbc1c6d27 618 q[3] = q4 * norm;
demayer 1:b36bbc1c6d27 619
demayer 1:b36bbc1c6d27 620 }
demayer 1:b36bbc1c6d27 621
demayer 1:b36bbc1c6d27 622
demayer 1:b36bbc1c6d27 623 void MPU9250::readIMU()
demayer 1:b36bbc1c6d27 624 {
demayer 1:b36bbc1c6d27 625 // If intPin goes high, all data registers have new data
demayer 2:c7897a3f5f11 626 if(readByte(MPU9250_ADDRESS, INT_STATUS) & 0x01) { // On interrupt, check if data ready interrupt
demayer 1:b36bbc1c6d27 627
demayer 2:c7897a3f5f11 628 readAccelData(accelCount); // Read the x/y/z adc values
demayer 1:b36bbc1c6d27 629 // Now we'll calculate the accleration value into actual g's
demayer 1:b36bbc1c6d27 630 ax = (float)accelCount[0]*aRes - accelBias[0]; // get actual g value, this depends on scale being set
demayer 1:b36bbc1c6d27 631 ay = (float)accelCount[1]*aRes - accelBias[1];
demayer 1:b36bbc1c6d27 632 az = (float)accelCount[2]*aRes - accelBias[2];
demayer 1:b36bbc1c6d27 633
demayer 2:c7897a3f5f11 634 readGyroData(gyroCount); // Read the x/y/z adc values
demayer 1:b36bbc1c6d27 635 // Calculate the gyro value into actual degrees per second
demayer 1:b36bbc1c6d27 636 gx = (float)gyroCount[0]*gRes - gyroBias[0]; // get actual gyro value, this depends on scale being set
demayer 1:b36bbc1c6d27 637 gy = (float)gyroCount[1]*gRes - gyroBias[1];
demayer 1:b36bbc1c6d27 638 gz = (float)gyroCount[2]*gRes - gyroBias[2];
demayer 1:b36bbc1c6d27 639
demayer 2:c7897a3f5f11 640 readMagData(magCount); // Read the x/y/z adc values
demayer 1:b36bbc1c6d27 641 // Calculate the magnetometer values in milliGauss
demayer 1:b36bbc1c6d27 642 // Include factory calibration per data sheet and user environmental corrections
demayer 1:b36bbc1c6d27 643 mx = (float)magCount[0]*mRes*magCalibration[0] - magbias[0]; // get actual magnetometer value, this depends on scale being set
demayer 1:b36bbc1c6d27 644 my = (float)magCount[1]*mRes*magCalibration[1] - magbias[1];
demayer 1:b36bbc1c6d27 645 mz = (float)magCount[2]*mRes*magCalibration[2] - magbias[2];
demayer 1:b36bbc1c6d27 646 }
demayer 2:c7897a3f5f11 647
demayer 1:b36bbc1c6d27 648
demayer 2:c7897a3f5f11 649
demayer 2:c7897a3f5f11 650 //pc.printf("ax, ay, az, delta_t;%f;%f;%f;%f\n\r", ax, ay, az*GRAVITATION + GRAVITATION, deltat);
demayer 1:b36bbc1c6d27 651
demayer 1:b36bbc1c6d27 652 Now = t.read_us();
demayer 1:b36bbc1c6d27 653
demayer 1:b36bbc1c6d27 654 deltat = (float)((Now - lastUpdate)/1000000.0f) ; // set integration time by time elapsed since last filter update
demayer 1:b36bbc1c6d27 655 lastUpdate = Now;
demayer 2:c7897a3f5f11 656
demayer 2:c7897a3f5f11 657 //pc.printf("%f,%f,%f,%f\n\r",ax, ay, az, deltat);
demayer 2:c7897a3f5f11 658
demayer 1:b36bbc1c6d27 659
demayer 1:b36bbc1c6d27 660 sum += deltat;
demayer 1:b36bbc1c6d27 661 sumCount++;
demayer 1:b36bbc1c6d27 662
demayer 1:b36bbc1c6d27 663 // Pass gyro rate as rad/s
demayer 2:c7897a3f5f11 664 MadgwickQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
demayer 1:b36bbc1c6d27 665 //mpu9250.MahonyQuaternionUpdate(ax, ay, az, gx*PI/180.0f, gy*PI/180.0f, gz*PI/180.0f, my, mx, mz);
demayer 1:b36bbc1c6d27 666
demayer 1:b36bbc1c6d27 667 // Serial print and/or display at 0.5 s rate independent of data rates
demayer 1:b36bbc1c6d27 668 delt_t = t.read_ms() - _count;
demayer 2:c7897a3f5f11 669 //pc.printf("Zeit intern: %d\n\r", t.read_ms());
demayer 2:c7897a3f5f11 670 }
demayer 1:b36bbc1c6d27 671
demayer 2:c7897a3f5f11 672
demayer 2:c7897a3f5f11 673
demayer 2:c7897a3f5f11 674 /*//-----------------------------------------
demayer 2:c7897a3f5f11 675 // Update displayed value
demayer 2:c7897a3f5f11 676 if (delt_t > SAMPLE_TIME) {
demayer 1:b36bbc1c6d27 677
demayer 1:b36bbc1c6d27 678
demayer 1:b36bbc1c6d27 679
demayer 2:c7897a3f5f11 680 //pc.printf("vx, vy, vz: %f %f %f\n\r", v_trans[0], v_trans[1], v_trans[2]);
demayer 2:c7897a3f5f11 681
demayer 2:c7897a3f5f11 682
demayer 2:c7897a3f5f11 683 yaw = atan2(2.0f * (q[1] * q[2] + q[0] * q[3]), q[0] * q[0] + q[1] * q[1] - q[2] * q[2] - q[3] * q[3]);
demayer 2:c7897a3f5f11 684 pitch = -asin(2.0f * (q[1] * q[3] - q[0] * q[2]));
demayer 2:c7897a3f5f11 685 roll = atan2(2.0f * (q[0] * q[1] + q[2] * q[3]), q[0] * q[0] - q[1] * q[1] - q[2] * q[2] + q[3] * q[3]);
demayer 2:c7897a3f5f11 686 pitch *= 180.0f / PI;
demayer 2:c7897a3f5f11 687 yaw *= 180.0f / PI;
demayer 2:c7897a3f5f11 688 yaw -= 2.93f; // Declination at 8572 Berg TG: +2° 56'
demayer 2:c7897a3f5f11 689 roll *= 180.0f / PI;
demayer 2:c7897a3f5f11 690
demayer 1:b36bbc1c6d27 691
demayer 1:b36bbc1c6d27 692
demayer 2:c7897a3f5f11 693 myled= !myled;
demayer 2:c7897a3f5f11 694 _count = t.read_ms();
demayer 1:b36bbc1c6d27 695
demayer 2:c7897a3f5f11 696 if(_count > 1<<21) {
demayer 2:c7897a3f5f11 697 t.start(); // start the timer over again if ~30 minutes has passed
demayer 2:c7897a3f5f11 698 _count = 0;
demayer 2:c7897a3f5f11 699 deltat= 0;
demayer 2:c7897a3f5f11 700 lastUpdate = t.read_us();
demayer 2:c7897a3f5f11 701 }
demayer 2:c7897a3f5f11 702 sum = 0;
demayer 2:c7897a3f5f11 703 sumCount = 0;
demayer 2:c7897a3f5f11 704 }*/
demayer 1:b36bbc1c6d27 705
demayer 1:b36bbc1c6d27 706
demayer 1:b36bbc1c6d27 707
demayer 1:b36bbc1c6d27 708 void MPU9250::imuSetup()
demayer 1:b36bbc1c6d27 709 {
demayer 1:b36bbc1c6d27 710 //Set up I2C
demayer 1:b36bbc1c6d27 711 i2c.frequency(400000); // use fast (400 kHz) I2C
demayer 1:b36bbc1c6d27 712
demayer 2:c7897a3f5f11 713 pc->printf("CPU SystemCoreClock is %d Hz\r\n", SystemCoreClock);
demayer 1:b36bbc1c6d27 714
demayer 1:b36bbc1c6d27 715 t.start();
demayer 1:b36bbc1c6d27 716 // lcd.setBrightness(0.05);
demayer 1:b36bbc1c6d27 717
demayer 1:b36bbc1c6d27 718
demayer 1:b36bbc1c6d27 719 // Read the WHO_AM_I register, this is a good test of communication
demayer 2:c7897a3f5f11 720 uint8_t whoami = readByte(MPU9250_ADDRESS, WHO_AM_I_MPU9250); // Read WHO_AM_I register for MPU-9250
demayer 2:c7897a3f5f11 721 pc->printf("I AM 0x%x\n\r", whoami);
demayer 2:c7897a3f5f11 722 pc->printf("I SHOULD BE 0x71\n\r");
demayer 1:b36bbc1c6d27 723
demayer 1:b36bbc1c6d27 724 if (whoami == 0x71) { // WHO_AM_I should always be 0x68
demayer 2:c7897a3f5f11 725 pc->printf("MPU9250 WHO_AM_I is 0x%x\n\r", whoami);
demayer 2:c7897a3f5f11 726 pc->printf("MPU9250 is online...\n\r");
demayer 1:b36bbc1c6d27 727 sprintf(buffer, "0x%x", whoami);
demayer 1:b36bbc1c6d27 728 wait(1);
demayer 1:b36bbc1c6d27 729
demayer 2:c7897a3f5f11 730 resetMPU9250(); // Reset registers to default in preparation for device calibration
demayer 2:c7897a3f5f11 731 MPU9250SelfTest(SelfTest); // Start by performing self test and reporting values
demayer 2:c7897a3f5f11 732 pc->printf("x-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[0]);
demayer 2:c7897a3f5f11 733 pc->printf("y-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[1]);
demayer 2:c7897a3f5f11 734 pc->printf("z-axis self test: acceleration trim within : %f % of factory value\n\r", SelfTest[2]);
demayer 2:c7897a3f5f11 735 pc->printf("x-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[3]);
demayer 2:c7897a3f5f11 736 pc->printf("y-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[4]);
demayer 2:c7897a3f5f11 737 pc->printf("z-axis self test: gyration trim within : %f % of factory value\n\r", SelfTest[5]);
demayer 2:c7897a3f5f11 738 calibrateMPU9250(gyroBias, accelBias); // Calibrate gyro and accelerometers, load biases in bias registers
demayer 2:c7897a3f5f11 739 pc->printf("x gyro bias = %f\n\r", gyroBias[0]);
demayer 2:c7897a3f5f11 740 pc->printf("y gyro bias = %f\n\r", gyroBias[1]);
demayer 2:c7897a3f5f11 741 pc->printf("z gyro bias = %f\n\r", gyroBias[2]);
demayer 2:c7897a3f5f11 742 pc->printf("x accel bias = %f\n\r", accelBias[0]);
demayer 2:c7897a3f5f11 743 pc->printf("y accel bias = %f\n\r", accelBias[1]);
demayer 2:c7897a3f5f11 744 pc->printf("z accel bias = %f\n\r", accelBias[2]);
demayer 1:b36bbc1c6d27 745 wait(2);
demayer 2:c7897a3f5f11 746 initMPU9250();
demayer 2:c7897a3f5f11 747 pc->printf("MPU9250 initialized for active data mode....\n\r"); // Initialize device for active mode read of acclerometer, gyroscope, and temperature
demayer 2:c7897a3f5f11 748 initAK8963(magCalibration);
demayer 2:c7897a3f5f11 749 pc->printf("AK8963 initialized for active data mode....\n\r"); // Initialize device for active mode read of magnetometer
demayer 2:c7897a3f5f11 750 pc->printf("Accelerometer full-scale range = %f g\n\r", 2.0f*(float)(1<<Ascale));
demayer 2:c7897a3f5f11 751 pc->printf("Gyroscope full-scale range = %f deg/s\n\r", 250.0f*(float)(1<<Gscale));
demayer 2:c7897a3f5f11 752 if(Mscale == 0) pc->printf("Magnetometer resolution = 14 bits\n\r");
demayer 2:c7897a3f5f11 753 if(Mscale == 1) pc->printf("Magnetometer resolution = 16 bits\n\r");
demayer 2:c7897a3f5f11 754 if(Mmode == 2) pc->printf("Magnetometer ODR = 8 Hz\n\r");
demayer 2:c7897a3f5f11 755 if(Mmode == 6) pc->printf("Magnetometer ODR = 100 Hz\n\r");
demayer 1:b36bbc1c6d27 756 wait(1);
demayer 1:b36bbc1c6d27 757 } else {
demayer 2:c7897a3f5f11 758 pc->printf("Could not connect to MPU9250: \n\r");
demayer 2:c7897a3f5f11 759 pc->printf("%#x \n", whoami);
demayer 1:b36bbc1c6d27 760 sprintf(buffer, "WHO_AM_I 0x%x", whoami);
demayer 1:b36bbc1c6d27 761
demayer 1:b36bbc1c6d27 762 while(1) {
demayer 1:b36bbc1c6d27 763 // Loop forever if communication doesn't happen
demayer 2:c7897a3f5f11 764 pc->printf("no IMU detected (verify if it's plugged in)\n\r");
demayer 1:b36bbc1c6d27 765 }
demayer 1:b36bbc1c6d27 766 }
demayer 1:b36bbc1c6d27 767
demayer 2:c7897a3f5f11 768 getAres(); // Get accelerometer sensitivity
demayer 2:c7897a3f5f11 769 getGres(); // Get gyro sensitivity
demayer 2:c7897a3f5f11 770 getMres(); // Get magnetometer sensitivity
demayer 2:c7897a3f5f11 771 pc->printf("Accelerometer sensitivity is %f LSB/g \n\r", 1.0f/aRes);
demayer 2:c7897a3f5f11 772 pc->printf("Gyroscope sensitivity is %f LSB/deg/s \n\r", 1.0f/gRes);
demayer 2:c7897a3f5f11 773 pc->printf("Magnetometer sensitivity is %f LSB/G \n\r", 1.0f/mRes);
demayer 1:b36bbc1c6d27 774 magbias[0] = +470.; // User environmental x-axis correction in milliGauss, should be automatically calculated
demayer 1:b36bbc1c6d27 775 magbias[1] = +120.; // User environmental x-axis correction in milliGauss
demayer 1:b36bbc1c6d27 776 magbias[2] = +125.; // User environmental x-axis correction in milliGauss
demayer 1:b36bbc1c6d27 777 }
demayer 1:b36bbc1c6d27 778
demayer 2:c7897a3f5f11 779
demayer 2:c7897a3f5f11 780 // N Werte sammeln, Integrale aufsummieren
demayer 2:c7897a3f5f11 781 /*float MPU9250::getMedianAcc(){
demayer 2:c7897a3f5f11 782 int8_t i;
demayer 2:c7897a3f5f11 783 ax_sum = 0;
demayer 2:c7897a3f5f11 784 for (i=0; i<STEP_NUMBER; i++) {
demayer 2:c7897a3f5f11 785 readIMU();
demayer 2:c7897a3f5f11 786 //pc.printf("Zeit extern: %d\n\n\r", t.read_ms());
demayer 2:c7897a3f5f11 787 pc.printf("i=%d: ax=%f\n\r", i, ax);
demayer 2:c7897a3f5f11 788 ax_sum += ax;
demayer 2:c7897a3f5f11 789 }
demayer 2:c7897a3f5f11 790 pc.printf("Summe: %f\n\n\r", ax_sum/steps);
demayer 2:c7897a3f5f11 791 return ax_sum/steps;
demayer 2:c7897a3f5f11 792 }*/
demayer 2:c7897a3f5f11 793
demayer 2:c7897a3f5f11 794
demayer 2:c7897a3f5f11 795 // BufferArray-Variante
demayer 2:c7897a3f5f11 796 float MPU9250::getVBuffer()
demayer 2:c7897a3f5f11 797 {
demayer 2:c7897a3f5f11 798 // Save the last ax value before readIMU() is executed
demayer 2:c7897a3f5f11 799 float ax_old = ax;
demayer 1:b36bbc1c6d27 800
demayer 2:c7897a3f5f11 801 // Save the last vx value
demayer 2:c7897a3f5f11 802 if (stepCounter == 0) {
demayer 2:c7897a3f5f11 803 vx_old = vx_buffer[STEP_NUMBER-1];
demayer 2:c7897a3f5f11 804 }
demayer 2:c7897a3f5f11 805 else{
demayer 2:c7897a3f5f11 806 vx_old = vx_buffer[stepCounter - 1];
demayer 2:c7897a3f5f11 807 }
demayer 2:c7897a3f5f11 808
demayer 2:c7897a3f5f11 809
demayer 2:c7897a3f5f11 810 // Sets new ax value
demayer 2:c7897a3f5f11 811 readIMU();
demayer 2:c7897a3f5f11 812
demayer 2:c7897a3f5f11 813
demayer 2:c7897a3f5f11 814 // Calculate Integration Step of new and old value
demayer 2:c7897a3f5f11 815 vx_buffer[stepCounter] = vx_old + deltat*0.5f*(ax + ax_old)/GRAVITATION;
demayer 2:c7897a3f5f11 816
demayer 2:c7897a3f5f11 817 int i;
demayer 2:c7897a3f5f11 818 float vx_median = 0;
demayer 2:c7897a3f5f11 819 for (i=0; i<STEP_NUMBER; i++) {
demayer 2:c7897a3f5f11 820 vx_median += vx_buffer[i];
demayer 2:c7897a3f5f11 821 //pc.printf("%d: %f\n\r", i, vx_buffer[i]);
demayer 2:c7897a3f5f11 822 }
demayer 2:c7897a3f5f11 823 //pc.printf("\n\r");
demayer 2:c7897a3f5f11 824 //pc.printf("%f,%f,%f,%f\n\r", ax, vx_median/STEP_NUMBER, vx_buffer[stepCounter], deltat);
demayer 2:c7897a3f5f11 825
demayer 2:c7897a3f5f11 826 stepCounter++;
demayer 2:c7897a3f5f11 827 if (stepCounter >= STEP_NUMBER) {
demayer 2:c7897a3f5f11 828 stepCounter = 0;
demayer 2:c7897a3f5f11 829 }
demayer 2:c7897a3f5f11 830 return vx_median/STEP_NUMBER;
demayer 2:c7897a3f5f11 831 }